How to introduce FLR

I (21f) am currently in a relationship with my bf (21m) and he is a foreign student here and I am his first gf. I have always been dominant but never acted in a relationship. However, from the past two weeks I have decided that when he cums inside me he has to clean it and he does. Now I want to take a step forward so what are some things I can do ?

Specially, the experienced people in this area, please help me out